The FTDX5000 comes standard with a 3 kHz roofing filter in the SSB position and a 600 Hz roofing filter in the CW position. While the performance of these filter is good, for those seeking better performance, Inrad offers 2.4 kHz (#2310), 2.1 kHz (#2309), 1.8 kHz (#2308), and 500 Hz (#2304) filter options for this radio. Not only is the bandwidth narrower, but the skirts are steeper, offering
improved performance under heavy QRM conditions.